Role of stomata in minimizing photorespiration

Q. Stomata opens during the day and closes during the night because

1. Enzymes convert starch into sugar during the night
2. Photosynthesis takes place during daytime only
3. Formation of sugar increases osmotic concentration of cell sap which results in absorption of water which provide turgidity to guard cells
4. None of the above

Q.

From where do root hair carry out exchange of oxygen and carbon dioxide?

1. By breaking soil particles and absorbing air present inside them.

2. Root hairs do not need to exchange gases as this is done by leaves of the plant.

3. Root hairs exchange gases to and from tiny air pockets present in between soil particles.

4. Root hairs of land plants absorb the dissolved oxygen in water to breathe.

Q.

What are the methods used by plants to get rid of wastes? [3 MARKS]

Q.

How does stomatal action contribute to the regulation of the plants temperature?

Q. Closed stomata reduces

1. Rate of transpiration
2. Amount of carbon dioxide entering the leaf
3. Rate of respiration
4. Both rate of transpiration and amount of carbon dioxide entering the leaf

Q.

C4 plants, by decreasing photorespiration and efficiently carrying out photosynthesis, can?

1. Decrease stomatal openings and thereby reduce water loss.

2. Decrease stomatal openings and thereby reduce leaf temperature.

3. Increase stomatal openings and thereby increase water loss.

4. Increase stomatal openings and thereby increase leaf temperature.